Samples of doped and undoped a-Si:H were deposited at temperatures ranging from 100 ºC to 350 ºC and then submitted to different dehydrogenation temperatures (from 350 ºC to 550 ºC) and times (from 1 h to 4 h). a-Si:H films were characterised after deposition through the measurements of specific material parameters such as: the optical gap, the conductivity at 25 ºC, the thermal activation energy of conductivity and its hydrogen con-tent. Hydrogen content was measured after each thermal treatment. Substrate dopant contamination from phosphorus-doped a-Si thin films was evaluated by SIMS after complete dehydrogenation and a junction depth of 0.1 μm was obtained. Dehydrogenation results show a strong dependence of the hydrogen content of the as-deposited film on the deposition temperature. Nevertheless, the dehydrogenation temperature seems to de-termine the final H content in a way almost independent from the initial content in the sample. H richer films dehydrogenate faster than films with lower hydrogen con-centration.
|Journal||Physica Status Solidi (C) Current Topics In Solid State Physics|
|Publication status||Published - 1 Jan 2012|